Display apparatus, method for controlling the same and image providing apparatus

ABSTRACT

A display apparatus displaying, a method for controlling the display apparatus, and an image providing apparatus. The display apparatus includes a communicator configured to receive image data of an image and brightness information of the image, a processor configured to generate a tone mapping curve by using the brightness information and to apply the tone mapping curve to the image data to provide tone mapped image data, and a display configured to display the image based on the tone-mapped image data.

CROSS-REFERENCE TO RELATED APPLICATION(S)

This application is based on and claims priority under 35 U.S.C. § 119to Korean Patent Application No. 10-2017-0154027, filed on Nov. 17,2017, in the Korean Intellectual Property Office, the disclosure ofwhich is incorporated by reference herein in its entirety

BACKGROUND 1. Field

Embodiments of the present disclosure relate to a display apparatusdisplaying, a method for controlling the same, and an image providingapparatus.

2. Description of Related Art

A display apparatus represents an apparatus that is capable ofconverting image data, which is stored therein and/or transmitted fromthe outside, into visual information so as to output the visualinformation in the form of screen. The display apparatus may include anelectronic board, a digital television, a monitor device, a smart phone,a tablet PC, a navigation device, an electronic billboard or a varietyof other devices capable of displaying images. The display apparatus maybe used for various purposes in various places such as a house or abusiness place.

The display apparatus may output an image to the outside using variousdisplays. The displays may include a cathode ray tube (CRT), a liquidcrystal display (LCD), a light emitting diode (LED), an organic lightemitting diode (OLED), an active organic light emitting diode orelectronic paper.

SUMMARY

Therefore, it is an aspect of the present disclosure to provide adisplay apparatus capable of directly generating a tone mapping functionapplied to an image to be displayed thereon, a method for controllingthe display apparatus, and an image providing apparatus.

Additional aspects of the present disclosure will be set forth in partin the description which follows and, in part, will be obvious from thedescription, or may be learned by practice of the present disclosure.

In accordance with an aspect of the disclosure, a display apparatusincludes a communicator configured to receive an image and informationon brightness of the image, a processor configured to acquire a tonemapping curve by using the brightness information and apply the tonemapping curve to the image, and a display configured to display an imageto which the tone mapping curve is applied.

The processor may generate the tone mapping curve based on the maximumbrightness of the display and acquire the tone mapping curve.

The brightness information may include percentile information ofbrightness distribution of the image.

The brightness distribution of the image may include a histogram that isacquired by accumulating the maximum value among R value, G value and Bvalue of each pixel of the image.

The communicator may further receive information on a reference tonemapping curve. The processor may generate the tone mapping curve byfurther using the reference tone mapping curve.

The processor may generate the tone mapping curve by comparing themaximum brightness of the display with the maximum brightnesscorresponding to the reference tone mapping curve.

The processor may select the reference tone mapping curve as the tonemapping curve when the maximum brightness of the display is the same asthe maximum brightness corresponding to the reference tone mappingcurve, and the processor may generate a tone mapping curve by using atleast one of the brightness information and the reference tone mappingcurve, and acquire the tone mapping curve, when the maximum brightnessof the display is different from the maximum brightness corresponding tothe reference tone mapping curve.

The processor may generate the tone mapping curve by increasing adistance between the origin and a knee point when the maximum brightnessof the display is greater than the maximum brightness corresponding tothe reference tone mapping curve, and the processor may generate thetone mapping curve by reducing a distance between the origin and theknee point when the maximum brightness of the display is less than themaximum brightness corresponding to the reference tone mapping curve.

The communicator may receive the image and the brightness information byusing High Definition Multimedia Interface (HDMI) standard.

In accordance with another aspect of the disclosure, an image providingapparatus includes a content obtainer configured to acquire an imagefile, a processor configured to decode the acquired image file andacquire at least one of information on brightness of an image and areference tone mapping curve from the decoded image information, and acommunicator configured to transmit at least one of the acquiredbrightness information of the image and the reference tone mappingcurve, to a display apparatus.

In accordance with another aspect of the disclosure, a method forcontrolling a display apparatus includes receiving an image andinformation on brightness of the image, acquiring a tone mapping curveby using the brightness information, applying the tone mapping curve tothe image, and displaying the image to which the tone mapping curve isapplied.

The acquiring of the tone mapping curve by using the brightnessinformation may include generating the tone mapping curve based on themaximum brightness of a display, and acquiring the tone mapping curve.

The brightness information may include percentile information ofbrightness distribution of the image.

The brightness distribution of the image may be acquired by accumulatingthe maximum value among R value, G value and B value of each pixel ofthe image.

The reception of the image and information on brightness of the imagemay include receiving the image, information on brightness of the image,and information on a reference tone mapping curve, and the acquiring ofthe tone mapping curve by using the brightness information may includegenerating the tone mapping curve by using the brightness informationand the reference tone mapping curve.

The generation of the tone mapping curve by using the brightnessinformation and the reference tone mapping curve may include comparingthe maximum brightness of the display with the maximum brightnesscorresponding to the reference tone mapping curve.

The generation of the tone mapping curve by using the brightnessinformation and the reference tone mapping curve may include at leastone of selecting the reference tone mapping curve as the tone mappingcurve when the maximum brightness of the display is the same as themaximum brightness corresponding to the reference tone mapping curve;and generating a tone mapping curve by using at least one of thebrightness information and the reference tone mapping curve andacquiring the tone mapping curve, when the maximum brightness of thedisplay is different from the maximum brightness corresponding to thereference tone mapping curve.

The generation of the tone mapping curve by using at least one of thebrightness information and the reference tone mapping curve andacquiring the tone mapping curve, when the maximum brightness of thedisplay is different from the maximum brightness corresponding to thereference tone mapping curve, may include at least one of generating thetone mapping curve by increasing a distance between the origin and aknee point when the maximum brightness of the display is greater thanthe maximum brightness corresponding to the reference tone mappingcurve, and generating the tone mapping curve by reducing a distancebetween the origin and the knee point when the maximum brightness of thedisplay is less than the maximum brightness corresponding to thereference tone mapping curve.

The reception of the image and information on brightness of the imagemay include receiving the image and the brightness information by usingHigh Definition Multimedia Interface (HDMI) standard.

BRIEF DESCRIPTION OF THE DRAWINGS

These and/or other aspects of the disclosure will become apparent andmore readily appreciated from the following description of embodiments,taken in conjunction with the accompanying drawings of which:

FIG. 1 is a schematic diagram of an image providing system according toan embodiment;

FIG. 2 is a block diagram of a display apparatus according to anembodiment;

FIG. 3 is a first view illustrating information on brightness of animage;

FIG. 4 is a second view illustrating information on brightness of animage;

FIG. 5 is a view illustrating a part of a transmission format that isreceived from an image producer terminal apparatus by the displayapparatus;

FIG. 6 is a view of an embodiment of a tone mapping curve;

FIG. 7 is a view illustrating an example in which the display apparatusgenerates a tone mapping curve;

FIG. 8A is a view illustrating an example of a variation of an imagedepending on applying a tone mapping curve;

FIG. 8B is a view illustrating an example of a variation of an imagedepending on applying a tone mapping curve;

FIG. 9 is a block diagram illustrating an embodiment of an imageproviding apparatus and a display apparatus;

FIG. 10 is a schematic diagram of an image providing system according toanother embodiment;

FIG. 11 is a block diagram illustrating a display apparatus according toanother embodiment;

FIG. 12 is a view illustrating an embodiment of a reference tone mappingcurve, and FIG. 13 is a view illustrating a part of a transmissionformat transmitted from the image providing apparatus to the displayapparatus;

FIG. 14 is a first view of acquiring a tone mapping curve based oninformation on brightness of image and a reference tone mapping curve;

FIG. 15 is a second view of acquiring a tone mapping curve based oninformation on brightness of image and a reference tone mapping curve;

FIG. 16 is a third view of acquiring a tone mapping curve based oninformation on brightness of image and a reference tone mapping curve;

FIG. 17 is a block diagram illustrating an image providing apparatusaccording to another embodiment;

FIG. 18 is a flowchart illustrating a method for controlling a displayapparatus according to an embodiment; and

FIG. 19 is a flowchart illustrating a method for controlling a displayapparatus according to another embodiment.

DETAILED DESCRIPTION

In the following description, like reference numerals refer to likeelements throughout the specification. Well-known functions orconstructions are not described in detail since they would obscure theone or more exemplar embodiments with unnecessary detail. Terms such as“unit”, “module”, “member”, and “block” may be embodied as hardware orsoftware. According to embodiments, a plurality of “unit”, “module”,“member”, and “block” may be implemented as a single component or asingle “unit”, “module”, “member”, and “block” may include a pluralityof components.

It will be understood that when an element is referred to as being“connected” another element, it can be directly or indirectly connectedto the other element, wherein the indirect connection includes“connection via a wireless communication network”.

Also, when a part “includes” or “comprises” an element, unless there isa particular description contrary thereto, the part may further includeother elements, not excluding the other elements.

It will be understood that, although the terms first, second, third,etc., may be used herein to describe various elements, but is should notbe limited by these terms. These terms are only used to distinguish oneelement from another element.

As used herein, the singular forms “a,” “an” and “the” are intended toinclude the plural forms as well, unless the context clearly indicatesotherwise.

Reference will now be made in detail to embodiments of the presentdisclosure, examples of which are illustrated in the accompanyingdrawings.

FIG. 1 is a schematic diagram of an image providing system according toan embodiment.

As illustrated in FIG. 1, according to an embodiment, in order toprovide an image to a display apparatus 100, an image providing system 1may include the display apparatus 100, an image producer terminalapparatus 9 configured to produce an image file 10 related to an imageto be displayed on the display apparatus 100, and a storage medium 7 ora transmitter 8 configured to directly or indirectly transmit the imagefile 10 produced by the image producer terminal apparatus 9.

The display apparatus 100 and an image providing apparatus 120 maydirectly receive video or audio data from the storage medium 7 havingthe image file 10.

In addition, the display apparatus 100, the image producer terminalapparatus 9, and the transmitter 8 may be configured to transmit data(e.g., the image file 10) to at least one direction via a wiredcommunication network, a wireless communication network or a networkthat is established by combining the wired communication network and thewireless communication network. The wired communication network may beconstructed using a cable. For example, the cable may be implementedusing a pair cable, a coaxial cable, a fiber optic cable, or an Ethernetcable. The wireless communication network may include at least one of alocal area network and a telecommunications network. For example, localarea network may be implemented by Wi-Fi, Bluetooth, Wi-Fi Direct,Bluetooth Low Energy, CAN communication, Zigbee and/or Near FieldCommunication (NFC). The telecommunication network may be implementedbased on a mobile communication standard such as 3GPP, 3GPP2 or WiMAXseries.

The display apparatus 100 may represent a device configured to displayan image. The display apparatus 100 may acquire image data 11 from theimage file 10 and visually display the acquired image on a screen.According to embodiments, the display apparatus 100 may acquire metadata12 from the image file 10 and perform certain image processing on theimage data 11 by using the metadata 12 and then visually display theimage, on which the image processing is performed, on a screen.

Particularly, the display apparatus 100 may acquire the metadata 12 ofthe image file 10 from the storage medium 7 such as an optical disc andperform the image processing on the image data 11 by using the metadata.The optical disc may be a UHD BD disc, but is not limited thereto.

The display apparatus 100 may receive the image file 10 from the imageproviding apparatus 120. That is, the display apparatus 100 may acquirethe metadata 12 from the image file 10 received by the image providingapparatus 120 via the storage medium 7, and perform the image processingof the image data 11 by using the metadata.

The display apparatus 100 may receive the image file 10 via the externalwired and/or wireless communication network, and/or receive the imagefile 10 from an external storage medium (not shown) and/or the imageproviding apparatus 120 connected through various terminals such asuniversal serial bus (USB) terminals, and High-definition multimediainterface (HDMI), provided in the display apparatus 100, or variouscables using a standard such as IEEE 1394.

The display apparatus 100 may include a digital TV, a monitor deviceconnected to a desktop computer (including a case in which a televisionreception card is mounted), a laptop computer, a smart phone, a tabletPC, a navigation device, an electronic billboard, an electronicblackboard, a projector, a portable game machine, a smart watch, a headmounted display (HMD) and/or various devices capable of outputtingimages.

The image producer terminal apparatus 9 may receive, select and/orgenerate the image file 10 for reproducing an image. The image producerterminal apparatus 9 may include a desktop computer, a laptop computer,a smartphone, a tablet PC and/or a linear editing system or a non-linearediting system which are specifically designed for image production. Inaddition, various devices capable of producing and editing an image maybe employed as the image producer terminal apparatus 9.

The image file 10 may be produced by being converted using a certaincodec. The certain codec may include H.26x codec (e.g., H.262 (MPEG2),H.263 (MPEG4), H.264 (AVC) and/or H.265 (HEVC)), WMV codec, WebM/VP9codec, Intel, Indeo, CinePak, ProRes or DNxHD codec. The image file 10may be produced by being compressed by a coder provided in the imageproducer terminal apparatus 9, based on the above mentioned codec.

The image file 10 may include the image data 11 (refer to FIG. 2) forreproducing an image and the metadata 12 (refer to FIG. 2) added to theimage data 11.

The image data 11 may represent data about an image itself to bereproduced. For example, the image data 11 may include information on aplurality of image frames. The image data 11 may include a predeterminednumber of image frames per second (for example, 24 or 30) according tothe format of the image file 10 or a reproduction method of the displayapparatus 100. The image may be formed by at least one scene. At leastone scene may be achieved by at least one cut formed by a set of imageframes. The image data 11 may be recorded in a body portion of the imagefile 10 to be transmitted.

The metadata 12 may include various kinds of information related to theimage data 11. For example, the metadata 12 may include at least onepiece of information on identification of the image data 11, informationon content of the image data 11, information on the copyright of theimage data 11, information on a reconstruction method of the image data11, information on search of the image data 11 and/or electronic programguide (EPG). The metadata 12 may be typically recorded in a headerportion of the image file 10 to be transmitted but is not limitedthereto.

The image file 10 may be transmitted to the display apparatus 100 via awire/wireless communication network. The image file 10 may betransmitted to the display apparatus 100 and/or the image providingapparatus 120 by the transmitter 8.

Alternatively, the image file 10 may be transmitted to the displayapparatus 100 such that the image file 10 is recorded on a recordingmedium, which is readable by a computer, and then the recording mediumis directly mounted to the display apparatus 100. In addition, the imagefile 10 may be transmitted to the display apparatus 100 such that theimage file 10 is recorded on a recording medium and the recording mediumis mounted to a separate reproduction device and then the image file 10is transmitted to the display apparatus 100 by an operation of thereproduction device. Recording medium readable by a computer may includea magnetic disk storage medium, a magnetic tape, an optical recordingmedium, and a semiconductor storage device. Particularly, the image file10 may be recorded in a recording medium such as a DVD or Blu-ray disc,and the reproduction device configured to play a DVD or blu-ray disc mayanalyze and transmit the image file 10 recorded on the recording medium,and/or transmit the image file 10 to the display apparatus 100 withoutan additional process. Therefore, the display apparatus 100 may displayan image corresponding to the image data 11 and/or the metadata 12, onthe screen.

A structure and operation of the display apparatus 100 and the metadata12 will be described later in details.

The transmitter 8 may transmit the image file 10 having the image data11 for reproducing an image and the metadata 12 added to the image data11, to the display apparatus 100.

The transmitter 8 may transmit the image data 11 for reproducing animage and the metadata 12 added to the image data 11, to the imageproviding apparatus 120. In this case, the transmitter 8 may receive theimage data 11 for reproducing an image and the metadata 12 added to theimage data 11, from the image producer terminal apparatus 9 through thewired and/or wireless communication network. For example, thetransmitter 8 may be implemented by broadcasting transmission equipmentused for various public broadcasting or cable broadcasting and/or acomputer apparatus (server) for providing streaming service or avideo-on-demand service.

Depending on embodiments, the transmitter 8 may be omitted. In thiscase, the image file 10 may be transmitted from the image producerterminal apparatus 9 to the display apparatus 100 or to the imageproviding apparatus 120 via the storage medium 7.

The image providing apparatus 120 may represent an apparatus configuredto receive the image file 10 and acquire data needed for reproducing animage from the received image file 10, and then provide the data to thedisplay apparatus 100.

The image providing apparatus 120 may acquire the image data 11 and/orthe metadata 12 from the image file 10, which is stored in the certainrecording medium such as DVD or blu-ray disc, and/or which is receivedfrom the storage medium 7 or the transmitter 8, and transmit theacquired image data 11 and/or metadata 12 to the display apparatus 100.As needed, the image providing apparatus 120 may further perform acertain image processing on the acquired image data 11.

The image providing apparatus 120 may be implemented by a DVD player, aBlu-ray player, a game console, a set-top box and/or a televisionreceiving card. In addition, the image providing apparatus 120 may beimplemented by a variety of apparatuses that acquire the image file 10,and transmit the image file 10 to the display apparatus 100 withperforming a certain process on the image file 10 or without performingthe certain process.

Hereinafter an operation of the display apparatus 100 will be describedin more detail.

FIG. 2 is a block diagram of a display apparatus according to anembodiment.

Referring to FIG. 2, according to an embodiment, the display apparatus100 may include a communicator 101 receiving the image file 10, aprocessor 110 performing an image processing on the received image file10, a display 103 displaying an image, and a storage 105 storing avariety of information required for an operation of the processor 110.

The communicator 101 may be communicably connected to at least one ofthe image producer terminal apparatus 9, the transmitter 8 and the imageproviding apparatus 120 to receive the image file 10 and transmit thereceived image file 10 to the processor 110. For example, thecommunicator 101 may include a terminal and related components connectedto the wired communication network or an antenna, a communication chipand related components connected to the wireless communication network.

The communicator 101 may receive the image file 10 by using a coaxcable, a digital visual interface (DVI), a high-definition multimediainterface (HDMI) standard or a thunderbolt, but is not limited thereto.

According to embodiments, the communicator 101 may further receive audiodata. As needed, audio data may be added to the image file 10 and thentransmitted.

According to embodiments, the communicator 101 may transmit or provideinformation related to whether the display apparatus 100 is capable ofperforming a certain function or not, to at least one of the imageproducer terminal apparatus 9, the transmitter 8 and the image providingapparatus 120.

For example, the communicator 101 may transmit information related towhether the display apparatus 100 supports high dynamic range (HDR) ornot, to at least one of the above mentioned apparatuses 8, 9 and 120.

For another example, the communicator 101 may communicate with at leastone of the above mentioned apparatuses 8, 9 and 120 and provide data toallow the display apparatus 100 to display information related whetherthe display apparatus 100 is capable of performing a certain function,by assigning a certain region of enhance display identification data(EDID).

Accordingly, at least one of the above mentioned apparatuses 8, 9 and120 may identify whether the display apparatus 100 is capable of afunction of high dynamic range and select whether to transmit certainmetadata 12 such as information on brightness 12-1 or information on areference tone mapping curve, based on a result of identification.

The processor 110 may acquire the image data 11 based on the image file10 transmitted from the communicator 101, and perform a certain imageprocessing on the image data 11 by using the metadata 12, therebyallowing the display 103 to output (display) the image on which theimage processing is performed, to the outside.

The processor 110 may include a central processing unit (CPU), amicrocontroller unit (MCU), a micro-processor (Micom), an applicationsprocessor (AP), an electronic controlling unit (ECU) and/or otherelectronics capable of various kinds of arithmetic processing andgenerating control signals. These devices may be implemented using oneor more semiconductor chips and associated components.

Referring to FIG. 2, according to an embodiment, the processor 110 mayinclude a metadata extractor 111 obtaining the metadata 12 from theimage file 10, a first image processor 113 performing a certain imageprocessing on the image data 11, a tone mapping curve generator 115generating a tone mapping curve 20 (refer to FIG. 6) about the imagedata 11 based on the metadata 12, a tone mapping curve applicator 117applying the tone mapping curve 20 to the image data 11, and a secondimage processor 119 performing an additional image processing as needed.At least one of the above mentioned components 113 to 119 may beomitted. For example, at least one between the first image processor 113and the second image processor 119 may be omitted. FIG. 2 illustratesthat the metadata extractor 111, the first image processor 113, the tonemapping curve generator 115, the tone mapping curve applicator 117 andthe second image processor 119 are separated from each other, which isfor convenience of description. Therefore, it should be understood thatthe above mentioned components 111 to 117 is not physically separatedfrom each other, and thus at least one of the above mentioned components111 to 117 may be physically or logically separated from each other,depending on embodiments.

The metadata extractor 111 may receive the image file 10 from thecommunicator 101 and then acquire the metadata 12 from the image file 10and then transmit the acquired metadata 12 to the tone mapping curvegenerator 115. Depending on embodiments, the metadata extractor 111 maytransmit the image file 10 or the image data 11, which is acquired fromthe image file 10, to at least one of the first image processor 113, thetone mapping curve applicator 117 and the second image processor 119.

According to an embodiment, the metadata 12 acquired by the metadataextractor 111 may include information on brightness 12-1. Theinformation 12-1 on brightness may include information indicatingbrightness of an image to be processed and/or to be reproduced.

FIG. 3 is a first view illustrating information on brightness of animage and FIG. 4 is a second view illustrating information on brightnessof an image. In FIG. 4, the x-axis represents brightness and the y-axisrepresents a detection frequency of a value corresponding to a specificbrightness detected from each pixel 11-a to 11-d.

Referring to FIG. 3, the image data 11 may include a plurality of pixels11-a to 11-d. The plurality of pixels 11-a to 11-d represents a minimumunit forming an image. The plurality of pixels 11-a to 11-d may includea plurality of sub-pixels 11-a 1 to 11-d 4 so that each pixel 11-a to11-d can express a specific color. For example, any one pixel such as afirst pixel 11-a may include a plurality of sub-pixels 11-a 1 to 11-a 4.The sub-pixels 11-a 1 to 11-a 4 may emit or not emit light in a certaincolor such as red color R, green color G and blue color B, to allow thefirst pixel 11-a to emit light in a certain color. FIG. 3 illustratesthat each pixel 11 a to 11 d includes four sub pixels 11-a 1 to 11 d 4having a sub pixel emitting red light, two sub pixels emitting greencolor, and a sub pixel emitting blue light, but the number of the subpixels 11-a 1 to 11-d 4, the kinds of color and/or the arrangementpattern of the color is not limited to FIG. 3. For example, six subpixels or more may be contained in a single pixel 11 a to 11 d or thesub pixels 11-a 1 to 11-d 4 may be configured such that one of the subpixels 11-a 1 to 11-d 4 emits white light.

The brightness information 12-1 may be obtained by using values of thesub-pixels 11-a 1 to 11-d 4 contained in each of the pixels 11-a to11-d. Particularly, for each of the pixels 11-a to 11-d, it is possibleto obtain the greatest brightness among the sub-pixels 11-a 1 to 11-d 4contained in each of the pixels 11-a to 11-d. When the greatest valuesof the brightness is accumulated, it is possible obtain a histogram or agraph 13 (hereinafter referred to as “histogram”) similar with thehistogram, as illustrated in FIG. 4. In this case, a value xmcorresponding to the most frequently obtained brightness is relativelyhigh in the histogram 13 and a value corresponding to the rarelyobtained brightness is relatively low in the histogram 13.

The brightness information 12-1 may be defined using the histogram 13acquired in this manner. For example, the brightness information 12-1may include percentile information based on the histogram 13. Thepercentile information represents that a specific value is how far froma reference value when the total data is 100. That is, the percentileinformation may be defined as the point at which a particular value islocated relative to the whole. For example, percentile information (itmay be referred to as Max RGB N % percentile information) of a specificvalue N % ile may be defined as a specific value x1 on the X-axis of thehistogram 13 that is to allow a ratio between an entire area of thehistogram 13 and an area from the origin 0 to have a ratio N %corresponding to a specific value N % ile. For example, percentileinformation of 50% ile may be defined as a value corresponding to aposition of 50% from a reference value (e.g., 0 (zero)) among all valuesof the histogram 13, and percentile information of 99% ile may bedefined as a value corresponding to a position of 99% from a referencevalue in the histogram 13.

The brightness information 12-1 may include a plurality of percentilesinformation. For example, the plurality of percentiles information mayinclude percentile(s) in which a specific value N % ile is defined as atleast one of 1% ile, 5% ile, 10% ile, 25% ile, 50% ile, 75% ile, 90%ile, 95% ile, 98% ile and 99% ile. In other words, the brightnessinformation 12-1 may include percentiles information corresponding to atleast one of 1% ile, 5% ile, 10% ile, 25% ile, 50% ile, 75% ile, 90%ile, 95% ile, 98% ile and 99% ile, but is not limited thereto. Aspecific value N % ile of the plurality of percentiles information maybe defined as more or less than the above mentioned value. In addition,a specific value N % ile of the plurality of percentiles information maybe defined partially differently or all differently from the abovementioned value.

The brightness information 12-1 may be defined for each frame or eachcut in the image data 11 or defined for each scene. In other words, theplurality of brightness information 12-1 may be defined by correspondingto each of a plurality of parts of a single image data 11.

Alternatively, the brightness information 12-1 may be defined for theentire image. That is, the brightness information 12-1 may be definedfor entire of one image data 11. The brightness information 12-1 definedfor each parts of the image data 11 may be used for performing dynamictone mapping and the brightness information 12-1 defined for the entireimage may be used for performing static tone mapping.

FIG. 5 is a view illustrating a part of a transmission format that isreceived from an image producer terminal apparatus by the displayapparatus.

Particularly, FIG. 5 illustrates Vendor Specific InfoFrame (VSIF)transmission format. By using H.265 (HEVC) codec, a compressed image isdecoded and thus a compression thereof is released to acquire anaudio/video signal. Metadata is acquired from Supplemental EnhancementInformation (SEI), and the audio/video signal is transmitted to thedisplay apparatus 100 via HDMI from the image producer terminalapparatus 9 and metadata information is transmitted. In this process,Vendor Specific InfoFrame (VSIF) transmission format is transmitted in astate in which the image producer terminal apparatus 9 is connected toHDMI to transmit the metadata

The brightness information 12-1 may be contained in SEI of the metadata12. The image producer terminal apparatus 9 may acquire the brightnessinformation 12-1 from the metadata 12 and the image producer terminalapparatus 9 may add the brightness information 12-1 to the VSIFtransmission format 12-2 and then transmit the VSIF transmission format12-2 having the brightness information 12-1 to the display apparatus100, as illustrated in FIG. 5.

Referring to FIG. 5, the brightness information 12-1 may be transmittedafter being contained in other areas 12 b to 12 k other than an area 12a in which the VSIF type code or length is stored.

The brightness information 12-1 may include a plurality of differentpercentile information such as information about each of 1% ile, 5% ile,10% ile, 25% ile, 50% ile, 75% ile, 90% ile, 95% ile, 98% ile and 99%ile.

Meanwhile, the disclosed brightness information 12-1 is not limited tothe VSIF format that is formed as HDMI by using the ST.2094-40 standard.Alternatively, the brightness information may be transmitted to thedisplay apparatus 100 by being contained in information that is assignedto a certain area of optical disc standard format such as playlist byreferring to an optical disc standard such as UHD BD disc or a BD disc.

Referring again to FIG. 2, the first image processor 113 may convert theimage data 11 to allow the processor 110 to apply a tone mapping curveto the image data 11. Particularly, the first image processor 113 mayacquire data in a certain form, to which the tone mapping curve isapplicable, by converting a transfer function (e.g., Electrical-OpticalTransfer Function (EOTF)) according to a certain standard (e.g., ST 2084standard). For example, the transfer function may be gamma (i.e.,brightness correction value) applied to the image data 11, and in thiscase, the first image processor 113 may release gamma from the imagedata 11 and convert the image data 11 into a form (e.g., a linear imagedata) to which an opto-optical Transfer function (OOTF) is applicable.The image data, which is acquired by the processing of the first imageprocessor 113, may be transmitted to the tone mapping curve applicator117.

The tone mapping curve generator 115 may generate a tone mapping curvebased on the brightness information 12-1 of the metadata 12.

FIG. 6 is a view of an embodiment of a tone mapping curve and FIG. 7 isa view illustrating an example in which the display apparatus generatesa tone mapping curve. In FIGS. 6 and 7, the x axis represents brightnessof an input image (original image), and the y axis represents brightnessof a display image (output image).

When the display apparatus 100 is capable of displaying the image withbrightness that is relatively lower or higher than the certainbrightness of the image data 11 although the image data 11 has certainbrightness as whole or for each cut or scene, the display apparatus 100may perform the tone mapping process to correct difference brightnessbetween the input image and the output image. For example, when thebrightness of the image data 11 is 1000 nit but the maximum brightnessof the display apparatus 100 is 500 nit, the display apparatus 100 maynot output the image data 11 with the proper brightness and thus thedisplay apparatus 100 may convert the brightness of the image data 11 byperforming a tone mapping process by using a certain conversion. Aconversion (function) used for the tone mapping process is a tonemapping curve.

A tone mapping curve 20 may be defined as a relation between the inputbrightness and the output brightness as illustrated in FIGS. 6 and 7. Inother words, when brightness of the original image data 11 is given toN10, the brightness of the output image may be changed into N01corresponding to N10 by applying the tone mapping curve 20 by theprocessor 110. In this case, the maximum value on the x axis of the tonemapping curve 20 may be defined as the maximum brightness of the imagefile 10 (e.g., 1000 nit) and the maximum value on the y axis of the tonemapping curve 20 may be defined as the maximum brightness of the imageoutput (e.g., 500 nit) by the display apparatus 100.

The tone mapping curve 20 may include a linear region A1 that isextended from origin (0) to a first point P11 and has a linear shape,and a non-linear region A2 extended from the first point P11 (kneepoint). For example, the non-linear region A2 may have nth orderfunction (N>1). Particularly, the non-linear region A2 may be given asquadratic function such as an equation 1.y=4(1−x)³ P ₁+6x ²(1−x)² P ₂+4x(1−3)³ P ₃ +x4   [Equation 1]

Alternatively, the non-linear region A2 of the tone mapping curve 20 maybe defined by using at least on nth order function designed by adesigner.

The tone mapping curve generator 115 may generate a tone mapping curvebased on the brightness information 12-1.

Particularly, the tone mapping curve generator 115 may acquire the firstpoint P11 by using at least two pieces of percentile information such aspercentile information of 50% ile 12 f and percentile information of 99%ile 12 k, in the brightness information 12-1. Particularly, the tonemapping curve generator 115 may divide the percentile information of 50%ile 12 f by any one (e.g., the greater value) of the percentileinformation of 99% ile 12 k and a predetermined maximum value, so as toacquire a first ratio therebetween. As needed, the tone mapping curvegenerator 115 may shift the percentile information of 50% ile 12 f toleft side or right side by a predetermined bit, and then divide theshifted value by any one of the percentile information of 99% ile 12 kand a predetermined maximum value, thereby acquiring a first ratio.

Sequentially, the tone mapping curve generator 115 may acquire a x axiscoordinate of the first point P11 by applying the first ratio to apredetermined function (e.g., ramp function).

In addition, the tone mapping curve generator 115 may divide the maximumbrightness of the input image by the maximum brightness of the outputimage so as to acquire a second ratio (it corresponds to a slope of thelinear part) therebetween. The tone mapping curve generator 115 mayacquire a y axis coordinate of the first point P11 by applying thesecond ratio to the acquired x axis coordinate of the first point P11.

As needed, the tone mapping curve generator 115 may adjust the acquiredfirst point P11. For example, the tone mapping curve generator 115 maypartially change the position of the first point P11 to allow the tonemapping curve 20 to have a S shape or to give a specific effect. In thiscase, the tone mapping curve generator 115 may change the position ofthe first point P11 by relatively reducing at least one of the x axiscoordinate value and the y axis coordinate value of the first point P11.

Accordingly, the tone mapping curve generator 115 may acquire a linearfunction L1 (i.e., a linear function between the origin (0) and thefirst point P11) in the linear region A1.

Subsequently, the tone mapping curve generator 115 may acquire afunction C0 about the non-linear region A2. For example, the tonemapping curve generator 115 may acquire a function C0 to C2 in thenon-linear region A2 by calculating each of coefficients of Nth orderfunction (e.g., P1, P2 and P3 of the equation 1).

In this case, the tone mapping curve generator 115 may acquire a firstcoefficient P1 of the equation 1 based on the slope of a straight lineL1 passing between the origin (0) and the first point P11. The tonemapping curve generator 115 may select the first coefficient P1 as thesame as the slope of the straight line L1 or acquire the firstcoefficient P1 by partially adjusting the slope of the straight line L1.

Subsequently, the tone mapping curve generator 115 may select at leastone point such as a second point P12 and a third point P13, in thenon-linear region A2, and then acquire a second coefficient P2 and athird coefficient P3 based on the first coefficient P1 and at least onepoint P12 and P13.

The tone mapping curve generator 115 may acquire coordinates of the atleast one point P12 and P13 based on the at least one brightnessinformation 12-1. In other words, the at least one point P12 and P13 maybe acquired based on the percentile information of a certain value N %ile.

Particularly, the tone mapping curve generator 115 may acquire a thirdratio by diving a difference between certain percentile information(e.g., percentile information of 50% ile 12 f) and other percentileinformation (e.g., percentile information of 0% ile) by any one (e.g.,the greater value) between certain percentile information (e.g.,percentile information of 95% ile 12 i) and a predetermined maximumvalue. In the same manner, the tone mapping curve generator 115 mayacquire a fourth ratio by diving a difference between certain percentileinformation (e.g., percentile information of 75% ile 12 g) and otherpercentile information (e.g., percentile information of 0% ile) by anyone (e.g., the greater value) between certain percentile information(e.g., percentile information of 95% ile 12 i) and a predeterminedmaximum value. In this case, a difference between certain percentileinformation and other percentile information may be shifted to left sideor right side by a predetermined bit and then divided. A differencebetween other certain percentile information and other percentileinformation may be also shifted in the same manner.

Subsequently, the tone mapping curve generator 115 may acquire a firstresult value corresponding to the third ratio by applying the thirdvalue to the predetermined function (e.g., the above mentioned rampfunction), and acquire a second result value corresponding to the fourthratio by applying the fourth value to the predetermined function. Thetone mapping curve generator 115 may acquire a first target value byinterpolating the two result values by using an average or weightedaverage methods. In this case, the tone mapping curve generator 115 mayapply a value (target_50_v2, target_50_v1, target_50_t11, andtarget_50_t12) related to the second point P12 to the predeterminedfunction. In addition, in the same manner, the tone mapping curvegenerator 115 may acquire a third result value corresponding to thethird ratio and a fourth result value corresponding to the fourth ratioby applying the third ratio and the fourth ratio together with a value(target_85_v2, target_85_v1, target_85_t11, and target_85_t12) relatedto the third point P13, to the predetermined function. The tone mappingcurve generator 115 may acquire a second target value by interpolatingthe two result values by using an average or weighted average methods.The tone mapping curve generator 115 may acquire y value y 50 of thesecond point P12 by calculating a ratio between a difference between ahorizontal line P11 y passing the first point P11 and the maximum value,and a difference between the horizontal line P11 y passing the firstpoint P11 and the first target value in the non-linear region A2. Inaddition, the tone mapping curve generator 115 may acquire y value y 85of the third point P13 by calculating a ratio between a differencebetween the horizontal line P11 y passing the first point P11 and themaximum value, and a difference between the horizontal line P11 ypassing the first point P11 and the second target value in thenon-linear region A2. Accordingly, the tone mapping curve generator 115may acquire the second coefficient P2 and the third coefficient P3 ofthe tone mapping curve 20 based on the x-axis coordinate x50 and they-axis coordinate y50 corresponding to the second point P12 and thex-axis coordinate x85 and the y-axis coordinate y85 corresponding to thethird point P13. Therefore, all coefficients P1 to P3 of the equation 1may be acquired and then the tone mapping curve 20 may be generated.

FIG. 8A is a view illustrating an example of a variation of an imagedepending on applying a tone mapping curve and FIG. 8B is a viewillustrating an example of a variation of an image depending on applyinga tone mapping curve.

The tone mapping curve applicator 117 may receive the tone mapping curve20 generated in the tone mapping curve generator 115 and the image data11 from the metadata extractor 111 or the first image processor 113,thereby applying the tone mapping curve 20 to the image data 11.

When the display apparatus 100 performs the static tone mapping, thetone mapping curve generator 115 may generate a single tone mappingcurve 20 a, as illustrated in FIG. 8A, and then the tone mapping curveapplicator 117 may apply the same tone mapping curve 20 a to all thecuts or scenes 11-1 to 11-3 in the image data 11. Therefore, the outputimage 13-1 to 13-3 corresponding to the cut or scent 11-1 to 11-3 may bechanged to have the same brightness or have the brightness similar witheach other. Accordingly, a relatively dark image 11-1 may be convertedinto a darker image 13-1 and then displayed. A relatively bright image11-3 may be converted into an image 13-3 having proper brightness andthen displayed.

When the display apparatus 100 performs the dynamic tone mapping, thetone mapping curve generator 115 may generate a plurality of tonemapping curves 20-1 to 20-3, as illustrated in FIG. 8B. The plurality oftone mapping curves 20-1 to 20-3 may be generated for each cut or eachscene. Accordingly, the tone mapping curve applicator 117 may apply thetone mapping curves 20-1 to 20-3 to all cuts or each scene in the imagedata 11. Particularly, the tone mapping curve applicator 117 may applycorresponding tone mapping curves to corresponding cut or scene or applythe same tone mapping curve to some of cuts or scenes. Therefore,brightness of the output image 13-1 to 13-3 corresponding to the allcuts or scenes 11-1 to 11-3 may be differently changed from each other(some cuts or scenes are changed to have the same brightness).Therefore, a relatively dark image 11-1 may be converted into arelatively bright and appropriate image 14-1 and then displayed and arelatively bright image 11-3 may be converted into a relatively dark andappropriate image 14-3 then displayed.

Referring again to FIG. 2, the second image processor 119 may change anoptical reference signal of the tone-mapped image, to an electricalreference signal. The second image processor 119 may perform a finalgamma processing on the tone-mapped image. A signal output by the secondimage processor 119 may be transmitted to the display 103.

The display 103 may display the tone-mapped image to the outside. Forexample, the display 103 may be implemented by using a display panel.The display panel may include a plasma display panel (PDP), a lightemitting diode (LED) display panel and/or a liquid crystal display(LCD). The light emitting diode (LED) display panel may include organiclight emitting diode (OLED). The organic light emitting diode (OLED) mayinclude Passive Matrix OLED (PMOLED), or Active Matrix OLED (AMOLED).Alternatively, depending on embodiments, the 190 may include cathode raytube (CRT). In addition, the display 103 may include at least one devicecapable of displaying a screen, other than the above mentioned examples.

The storage 105 may temporarily or non-temporarily store a variety ofinformation for the operation of the processor 110. For example, thestorage 105 may store a variety of applications (it is referred to as aprogram or an APP) related to the generation of the tone mapping curve20. The application may be stored and/or updated in the storage 105during the production or distribution of the display apparatus 100,and/or the application may be stored and/or updated after being receivedvia the electronic software distribution network. For example, thestorage 105 may include at least one of a main memory and an auxiliarymemory.

Hereinafter embodiments of using the image providing apparatus 120 toreceive the image file 10 will be described.

FIG. 9 is a block diagram illustrating an embodiment of an imageproviding apparatus and a display apparatus.

Referring to FIG. 9, according to an embodiment, the image providingapparatus 120 may include a content obtainer 121 acquiring the imagefile 10 including the image data 11 and the metadata 12, a processor 130acquiring metadata 12 from the acquired image file, a communicator 123transmitting the acquired metadata 12 to an external display apparatus140, and a storage 125 temporarily or non-temporarily store a variety ofinformation for an operation of the image providing apparatus 120.

The content obtainer 121 may be communicably connected to at least oneof the image producer terminal apparatus 9, the transmitter 8 and theimage providing apparatus 120. The content obtainer 121 may receive theimage file 10 and transmit the received image file 10 to the processor130.

Depending on embodiments, the content obtainer 121 may be replaced witha reader configured to be readable data from a mounted-recording medium(e.g., DVD or Blu-ray).

The processor 130 may acquire the image data 11 and the metadata 12 fromthe image file 10 transmitted from the content obtainer 121.Particularly, the processor 130 may include a decoder 131 decodingcompressed image data 10, and a metadata extractor 133 acquiring themetadata 12 from the decoded image data 10.

The decoder 131 may decode the image data 10 using a predeterminedcodec.

The metadata extractor 133 may acquire information on the brightnesscontained in the metadata 12 from the decoded image data 10. Inaddition, the decoder 131 may insert information on the acquiredbrightness into a VSIF format transmitted via HDMI.

The communicator 123 may transmit the image data 11 and the metadata 12having the brightness information to the display apparatus 140 by usingVSIF that is specified in HDMI standard. Alternatively, the communicator123 may be configured to communicate with a communicator 141 of thedisplay apparatus 140 based on the standard technology such as USB orIEEE 1394.

The display apparatus 140 may perform the image processing based on thereceived image data 11 and the metadata 12, and then display theprocessed image to the outside.

Particularly, the display apparatus 140 may include the communicator141, a display 143, a storage 145 and a processor 150.

The communicator 141 of the display apparatus 140 may receive the imagedata 11 and the metadata 12 from the image providing apparatus 120 andthen transmit it to the processor 150.

The processor 150 may generate the tone mapping curve 20 based on themetadata 12 and perform the image processing on the image data 11 byapplying the generated tone mapping curve 20 to the image data 11.According to an embodiment, the processor 150 may include a first imageprocessor 151, a tone mapping curve generator 153, a tone mapping curveapplicator 155 and a second image processor 157. Alternatively, some ofthe above mentioned components may be omitted. The first image processor151, the tone mapping curve generator 153, the tone mapping curveapplicator 155 and the second image processor 157 may be implemented aspractically same as or implemented by partially modifying the firstimage processor 113, the tone mapping curve generator 115, the tonemapping curve applicator 117 and the second image processor 119.Therefore, description thereof will be omitted.

The display 143 may output or display the image on which the tonemapping curve 20 is applied, and the storage 145 may store a variety ofapplications and data required for the operation of the processor 150.The display 143 and the storage 145 may be practically same as thedisplay 103 and the storage 105 of the display apparatus 100 and thus adescription thereof will be omitted.

Hereinafter another embodiment of the image providing system will bedescribed with reference to FIGS. 10 to 16. In describing anotherembodiment of the image providing system 2, descriptions of practicallythe same parts as the image providing system 1 according to theabove-described an embodiment may be omitted for avoiding redundantdescription. However, even if a description of a part of theconfiguration of the image providing system 2 is omitted, it should beunderstood that the image providing system 2 to be described later doesnot exclude the omitted structure, operation or method.

FIG. 10 is a schematic diagram of an image providing system according toanother embodiment and FIG. 11 is a block diagram illustrating a displayapparatus according to another embodiment.

As illustrated in FIG. 10, according to another embodiment, in order toprovide an image to a display apparatus 200, an image providing system 2may include the display apparatus 200, an image producer terminalapparatus 9 configured to produce an image file 10 a related to an imageto be displayed on the display apparatus 200, and an image providingapparatus 220 configured to provide the image file 10 a to the displayapparatus 200.

According to another embodiment, the image file 10 a may be transmittedfrom the image producer terminal apparatus 9 to the image providingapparatus 220 or the image file 10 a may be provided to the imageproviding apparatus 220 in the form of an optical disc. The imageproviding apparatus 220 may acquire metadata 12 from the image file 10 aand transmit the metadata 12 to the display apparatus 200.

Referring to FIG. 11, the image file 10 a transmitted from the imageproviding apparatus 220 to the display apparatus 200 may include theimage data 11 for reproducing an image and the metadata 12 added to theimage data 11. The metadata 12 may further include reference tonemapping curve 12-3, in addition to the brightness information 12-1.

FIG. 12 is a view illustrating an embodiment of a reference tone mappingcurve, and FIG. 13 is a view illustrating a part of a transmissionformat transmitted from the image providing apparatus to the displayapparatus.

As illustrated in FIG. 11, the image file 10 a may include the imagedata 11 for reproducing an image and the metadata 12 added to the imagedata 11.

The image data 11 and the metadata 12 transmitted to the displayapparatus 200 by the image providing apparatus 220 may further includethe reference tone mapping curve 12-3, in addition to the brightnessinformation 12-1.

In the same manner as an embodiment, the brightness information 12-1 mayrepresent information indicating brightness of the image data 11. Forexample, the brightness information 12-1 may include percentileinformation defined based on a histogram that is generated byaccumulating the greatest values of the brightness of the sub-pixels11-a 1 to 11-d 4 contained in each of the pixels 11-a to 11-d.

The reference tone mapping curve 12-3 represents a tone mapping curveabout image data 11 that is produced by the image producer terminalapparatus 9 or created and defined and/or defined by the image producer.The reference tone mapping curve 12-3 may be contained to the metadata12 and then provided to the display apparatus 200. Particularly, thereference tone mapping curve 12-3 may include a tone mapping curvegenerated based on brightness of a reference display apparatus. Thereference display apparatus may include a display apparatus provided inthe image producer terminal apparatus 9 (e.g., a display mounted to aterminal apparatus or a monitor device connected through a cable), or adisplay apparatus (not shown) separately provided from the imageproducer terminal apparatus 9.

Particularly, when a user of the image producer terminal apparatus 9(e.g., a content creator) produces an image by using the image producerterminal apparatus 9, the image producer terminal apparatus 9 maygenerate the reference tone mapping curve 12-3 that is a tone mappingcurve applicable to an image by using the reference display apparatusthat is the maximum brightness corresponding to the reference tonemapping curve, wherein the image producer terminal apparatus 9 maygenerate the reference tone mapping curve 12-3 by an operation of theuser or the image producer terminal apparatus 9 may automaticallygenerate the reference tone mapping curve 12-3 by a predeterminedsetting. The reference tone mapping curve 12-3 may be defined for eachframe or each cut or each scene in the image data 11. In other words, aplurality of reference tone mapping curves 12-3 may be contained in asingle image file 10 a. The plurality of reference tone mapping curves12-3 may be used in the operation of the dynamic tone mapping process.In addition, the reference tone mapping curve 12-3 may be defined forthe entire image. In other words, one reference tone mapping curve 12-3may be contained in one image file 10 a. One reference tone mappingcurve 12-3 may be used in the static tone mapping process.

Depending on embodiments, the image producer terminal apparatus 9 maygenerate the reference tone mapping curve 12-3 based on the maximumbrightness (e.g., 1000 nit) of the produced image and/or or the maximumbrightness (e.g., 500 nit) of the reference display apparatus.

In this case, the metadata 12 transmitted to the display apparatus 200may include the maximum brightness 12-3.

The maximum brightness of the image may be equal to or different fromthe maximum brightness of the reference display apparatus. In the lattercase, the maximum brightness of the image may be greater than themaximum brightness of the reference display apparatus, or the maximumbrightness of the image may be less than the maximum brightness of thereference display apparatus.

Referring to FIG. 13, the image providing apparatus 220 may acquire thebrightness information 12-1 (distribution_maxrgb_percentiles), thereference tone mapping curve (Knee point 12-4 a, andBezier_curve_anchors 12-4 b), and the brightness of the referencedisplay apparatus 12-5 (targeted_system_display_maximum_luminance), fromthe image data and the metadata transmitted from the image producerterminal apparatus 9 or the image data and the metadata 11 acquired bydecoding the optical disc.

Each piece of information may be contained in the SEI section of theimage file 10 a produced by the image producer terminal apparatus 9.

Each piece of information may be contained in the SEI section that isacquired by decoding content that is encoded in the optical disc.

Each piece of information may be contained in a playlist section that isacquired by decoding content that is encoded in the optical disc.

The image providing apparatus 220 may acquire each piece of informationcontained in the SEI section, insert the acquired information into theVSIF structure of FIG. 13, and transmit the information to the displayapparatus 200 through the HDMI.

The brightness information 12-1, particularly, different pluralitypieces of percentiles information (e.g., information about each of 1%ile, 5% ile, 10% ile, 25% ile, 50% ile, 75% ile, 90% ile, 95% ile, 98%ile and 99% ile) may be recorded in a first section 121.

The information 12-4 a and 12-4 b on the reference tone mapping curve12-3 may be assigned to a second section 12 m and a third section 12 ndifferent from the first section 121, and then transmitted to thedisplay apparatus via the HDMI. Particularly, information on a point P0corresponding to a knee point, that is placed on an end of the linearregion A1 of the reference tone mapping curve 12-3 may be assigned tothe second section 12 m and then transmitted to the display apparatusvia the HDMI. Information on the function (e.g., the equation 1)corresponding to the non-linear region A2 of the reference tone mappingcurve 12-3 may be assigned to the third section 12 n and thentransmitted to the display apparatus via the HDMI.

In this case, the information on the function corresponding to thenon-linear region A2 may include the coefficients (e.g., P1 to P9) ofthe function corresponding to the non-linear region A2. The coefficientof the function may be transmitted to the display apparatus via the HDMIcorresponding to the order of the function corresponding to thenon-linear region A2.

For example, as for a quadratic function, since information about thethree coefficients P1 to P3 is transmitted and since the tone mappingcurve is linear from the origin to the knee point P0 and thecoefficients of the function P1 to P9 from the knee point P0 to othersection are given, it may be possible to identify and acquire thereference tone mapping curve 12-3 based on only data stored in thesecond section 12 m and the third section 12 n.

The display apparatus 200 according to another embodiment will bedescribed in details with reference to FIG. 11 again. A description ofthe same parts as those shown in FIG. 2 will be omitted.

As illustrated in FIG. 11, the display apparatus 200 may include animage receiver 201, a processor 210 performing an image processing onthe received image file 10 a, a display 203 displaying an image and astorage 205 storing a variety of information needed for an operation ofthe processor 210.

The image receiver 201 may receive the image file 10 a transmitted bythe image providing apparatus 220 and transmit the received image file10 a including metadata having the brightness information 12-1 and thereference tone mapping curve 12-3, to the processor 210. The imagereceiver 201 may further receive audio data, as needed.

The processor 210 may perform a predetermined image processing on theimage data 11 based on the metadata 12 obtained from the image file 10 atransmitted from the image receiver 201.

The processor 210 may include a metadata extractor 211 obtaining themetadata 12 from the image file 10 a, a first image processor 213performing a certain image processing on the image data 11, a tonemapping curve generator 215 generating a tone mapping curve 30: 30-1 to30-4 (refer to FIGS. 14 to 16) about the image data 11 based on themetadata 12, a tone mapping curve applicator 217 applying the tonemapping curve 20 to the image data 11, and a second image processor 219performing an additional image processing as needed. As mentioned above,it should be understood that the above mentioned components 211 to 219is not physically separated from each other, and thus at least one ofthe above mentioned components 211 to 219 may be physically or logicallyseparated from each other, depending on embodiments.

The metadata extractor 211 may receive the image file 10 a from theimage receiver 201, acquire the metadata 12 from the transmitted imagefile 10 a, and transmit the acquired metadata 12 to the tone mappingcurve generator 215. For example, the first image processor 213 mayconvert the image data 11 to allow the tone mapping curve to be appliedthereto. The tone mapping curve applicator 217 may apply the tonemapping curve 30: 30-1 to 30-4 to the image data 11 by using the tonemapping curve generated in the tone mapping curve generator 215. Thesecond image processor 219 may change an optical reference signal of theimage, on which the tone mapping is performed by the tone mapping curveapplicator 217, to an electrical reference signal.

The function or operation of the metadata extractor 211, the first imageprocessor 213, the tone mapping curve applicator 217 and the secondimage processor 219 may practically be same as the metadata extractor111, the first image processor 113, the tone mapping curve applicator117 and the second image processor 119. Therefore, description thereofwill be omitted.

FIG. 14 is a first view of acquiring a tone mapping curve based oninformation on brightness of image and reference tone mapping curve,FIG. 15 is a second view of acquiring a tone mapping curve based oninformation on brightness of image and reference tone mapping curve, andFIG. 16 is a third view of acquiring a tone mapping curve based oninformation on brightness of image and reference tone mapping curve. InFIGS. 14 to 16, it is assumed that the maximum brightness of the imageis 1000 nit and the maximum brightness of the reference displayapparatus is 500 nit, but it is merely an example.

The tone mapping curve generator 215 may generate the tone mapping curve30: 30-1 to 30-4 by using the metadata 12

Particularly, the tone mapping curve generator 215 may compare themaximum brightness of the reference display apparatus 12-3 a with themaximum brightness of the display apparatus 200 (it represents themaximum brightness of the display 203, which is a pre-stored value inthe storage 205), and select or generate the tone mapping curve 30: 30-1to 30-4 based on the result of comparison.

As illustrated in FIG. 14, when the maximum brightness of the referencedisplay apparatus 12-3 a is the same as or similar with the maximumbrightness of the display apparatus 200 (e.g., the brightness of theboth display apparatus is 500 nit) the tone mapping curve generator 215may select the transmitted reference tone mapping curve 12-3 as a tonemapping curve 30 to be applied to the image data 11. In other words, theselected tone mapping curve 30 may be the same as the reference tonemapping curve 12-3. The selected tone mapping curve 30 may betransmitted to the tone mapping curve applicator 217.

As illustrated in FIG. 15, when the maximum brightness of the referencedisplay apparatus 12-3 a is different from the maximum brightness of thedisplay apparatus 200 and the maximum brightness of the referencedisplay apparatus 12-3 a is greater than the maximum brightness of thedisplay apparatus 200, the tone mapping curve generator 215 may generatea new tone mapping curve 30-1 and 30-2 based on the reference tonemapping curve 12-3.

For example, the tone mapping curve generator 215 may move the kneepoint P22 of the reference tone mapping curve 12-3 relatively closer tothe origin 0 to select a knee point P23 and P24 of the new tone mappingcurve 30-1 and 30-2 and calculate a function in a non-linear region A4and A5 starting from the selected knee point P23 and P24, thereby newlyacquiring tone mapping functions 30-1 and 30-2 based on the knee pointP23 and P24 and the function in the non-linear region A4 and A5.

According to an embodiment, the tone mapping curve generator 215 maymove the knee point P23 and P24 relatively closer to the origin 0 thanthe knee point P22 of the reference tone mapping curve 12-3, as thedifference between the maximum brightness of the reference displayapparatus 12-3 a and the maximum brightness of the display apparatus 200is greater (that is, the maximum brightness of the display apparatus 200is relatively less than the maximum brightness of the reference displayapparatus). For example, when the maximum brightness of the displayapparatus 200 is sufficiently low (e.g., 100 nit), the tone mappingcurve generator 215 may select the origin 0 or a point adjacent to theorigin 0 as the knee point P24, and when the maximum brightness of thedisplay apparatus 200 is relatively less low (e.g., 300 nit), the tonemapping curve generator 215 may select a point relatively far from theorigin 0 as the knee point P24.

Depending on embodiment, the tone mapping curve generator 215 may selectthe position of the knee point P23 and P24 proportionally according tothe maximum brightness of the display apparatus 200. In addition, thetone mapping curve generator 215 may select the position of the kneepoint P23 in a state in which the maximum brightness of the displayapparatus 200 is relatively low, based on the knee point P22 of thereference tone mapping curve 12-3 and based on the knee point P24 in astate in which the maximum brightness of the display apparatus 200 issufficiently low. For example, the tone mapping curve generator 215 mayselect the knee point P22 of the reference tone mapping curve 12-3 andthe knee point P24, in a state in which the maximum brightness of thedisplay apparatus 200 is sufficiently low, and then select the positionof the knee point P23, in a state in which the maximum brightness of thedisplay apparatus 200 is relatively low, by applying the predeterminedinterpolation method to the selected knee points P22 and P24.

Sequentially, the tone mapping curve generator 215 may calculate afunction about the non-linear region A4 and A5. Depending onembodiments, the tone mapping curve generator 215 may calculate afunction about the non-linear region A4 and A5 by using the coefficientsP1 to P9 of the reference tone mapping curve 12-3. Alternatively, thetone mapping curve generator 215 may calculate a function about thenon-linear region A4 and A5 based on the brightness information 12 thatis transmitted in FIG. 7.

Accordingly, the tone mapping curve generator 215 may acquire the tonemapping curves 30-1 and 30-2 corresponding to the maximum brightness ofthe display apparatus 200.

As illustrated in FIG. 16, when the maximum brightness of the referencedisplay apparatus 12-3 a is different from the maximum brightness of thedisplay apparatus 200 and the maximum brightness of the displayapparatus 200, which is to display an image, is greater than the maximumbrightness of the reference display apparatus 12-3 a, the tone mappingcurve generator 215 may generate new tone mapping curves 30-1 and 30-2.

For example, the tone mapping curve generator 215 may select knee pointsP33 and P34 of new tone mapping curves 30-3 and 30-4 by correcting theknee point P22 of the reference tone mapping curve 12-3 by moving theknee point P22 of the reference tone mapping curve 12-3 relatively farfrom the origin 0, and calculate a function in non-linear regions A7 andA8, thereby acquiring tone mapping functions 30-3 and 30-4.

According to an embodiment, in the same manner as the above mention, thetone mapping curve generator 215 may compare the maximum brightness ofthe reference display apparatus 12-3 a with the maximum brightness ofthe display apparatus 200 and when the maximum brightness of the displayapparatus 200 is greater than the maximum brightness of the referencedisplay apparatus 12-3 a, the tone mapping curve generator 215 mayacquire the tone mapping functions 30-3 and 30-4 based on the maximumbrightness of the display apparatus 200.

For example, as the maximum brightness of the display apparatus 200 isgreater (i.e., the maximum brightness of the display apparatus 200 isrelatively greater than the maximum brightness of the reference displayapparatus), the tone mapping curve generator 215 may select a point,which is farther from the origin 0 than the knee point P22 of thereference tone mapping curve 12-3, as the knee points P33 and P34. Inthis case, as the maximum brightness of the display apparatus 200 isrelatively greater, the tone mapping curve generator 215 may select apoint, which is farther from the origin 0 than the knee point P22 of thereference tone mapping curve 12-3, as the knee points P33 and P34. Forexample, when the maximum brightness of the display apparatus 200 issufficiently high (e.g., 1000 nit), the tone mapping curve generator 215may select a point, which is relatively far from the origin 0, (e.g.,the center point of the tone mapping cover 30-4), as the knee point P34.In this case, a function of the non-linear region A9 may be implementedin the linear function that is the same as the function of thenon-linear region A8. In addition, when the maximum brightness of thedisplay apparatus 200 is relatively less great (e.g., 700 nit), the tonemapping curve generator 215 may select a point, which is relatively lessfar from the origin 0, as the knee point P33.

Depending on embodiment, the tone mapping curve generator 215 may selectthe position of the knee point P33 and P34 proportionally according tothe maximum brightness of the display apparatus 200. The tone mappingcurve generator 215 may select the position of P33 in a state in whichthe maximum brightness of the display apparatus 200 is relatively lesslow, based on the knee point P22 of the reference tone mapping curve12-3 and based on the knee point P34 in a state in which the maximumbrightness of the display apparatus 200 is sufficiently high.

When the knee points P34 and P35 are selected, the tone mapping curvegenerator 215 may calculate a function about the non-linear regions A7and A8. The tone mapping curve generator 215 may calculate a functionabout the non-linear region A4 and A5 by using the coefficient P1 to P9of the tone mapping curve 12-3. Alternatively, the tone mapping curvegenerator 215 may calculate a function about the non-linear region A4and A5 based on the brightness information 12 that is transmitted inFIG. 7.

Accordingly, when the maximum brightness of the display apparatus 200 isrelatively high, the tone mapping curve generator 215 may generate andacquire the tone mapping curve 30-3 and 30-4 which are appropriate forthe display apparatus 200.

The tone mapping curve 30: 30-1 to 30-4 generated by the tone mappingcurve generator 215 may be transmitted to the tone mapping curveapplicator 217 and the tone mapping curve applicator 217 may apply thetone mapping curve 30: 30-1 to 30-4 to the image file 10 a.

Hereinbefore the operation of the tone mapping curve generator 215 whenthe maximum brightness of the image is 1000 nit and the maximumbrightness of the reference display apparatus is 500 nit, has beendescribed with reference to FIGS. 14 to 16. However, it should beunderstood that the above mentioned operation of the tone mapping curvegenerator 215 or specific values related thereto are merely example andthus the operation and the values may vary according to the conditionsor the designer's choice.

The display 203 and the storage 205 may be implemented as practicallysame as or implemented by partially modifying the display 103 and thestorage 105 of the display apparatus 100 according to an embodiment.Therefore, description thereof will be omitted.

Hereinafter another embodiment of the image providing system will bedescribed with an example in which the image providing apparatus 220 isused for the reception of the image file 10 a. In describing anotherembodiment of the image providing apparatus 220, descriptions ofpractically the same parts as the above-described an embodiment may beomitted for avoiding redundant description. However, even if adescription of a part of the configuration thereof is omitted, it shouldbe understood that the image providing system 2 to be described laterdoes not exclude the omitted structure, operation or method.

FIG. 17 is a block diagram illustrating an image providing apparatusaccording to another embodiment.

Referring to FIG. 17, according to another embodiment, the imageproviding apparatus 220 may include a content obtainer 221 acquiring theimage file 10 a including the image data 11 and the metadata 12, aprocessor 230 acquiring metadata 12 from the acquired image file, acommunicator 223 transmitting the acquired metadata 12 to an externaldisplay apparatus 240, and a storage 225 temporarily or non-temporarilystore a variety of information for an operation of the image providingapparatus 220.

The content obtainer 221 may receive the image file 10 a from at leastone of the image producer terminal apparatus 9, the transmitter 8 andthe image providing apparatus 220, and transmit the received image file10 a to the processor 230. Depending on embodiments, the image providingapparatus 220 may include a reader configured to read data from therecording medium, instead of the content obtainer 121.

The image file 10 a in the compressed type may be transmitted to theimage providing apparatus 220 from the image producer terminal apparatus9.

The processor 230 may acquire the image data 11 and the metadata 12 fromthe image file 10 a transmitted from the content obtainer 221.

Particularly, the image providing apparatus 220 may include a decoder231 decoding the compressed image file 10 a by using a predeterminedcodec, and a metadata extractor 233 acquiring the metadata 12 from thedecoded data. By the metadata extractor 233, the image providingapparatus 220 may acquire the brightness information 12-1, the referencetone mapping curve 12-3 and the maximum brightness 12-3 a from the imagefile 10 a.

The communicator 223 may be communicably connected to a communicator 241of a display apparatus 240 and transmit the image data 11 and theacquired metadata 12 to the display apparatus 240 through HDMI asillustrated in FIG. 13.

Therefore, the image providing apparatus 220 may transmit the brightnessinformation 12-1, the reference tone mapping curve 12-3 and the maximumbrightness 12-3 a to the display apparatus 240.

The display apparatus 240 may display an image corresponding to theimage data 11 on a display 243. However, before outputting the image,the display apparatus 240 may perform an image processing by using thebrightness information 12-1, the reference tone mapping curve 12-3 andthe maximum brightness 12-3 a, which are acquired and transmitted by theimage providing apparatus 220.

Particularly, a processor 250 of the display apparatus 240 may include afirst image processor 251 converting the image data 11 to allow the tonemapping curve to be applied to the image data 11, a tone mapping curvegenerator 253 generating a certain tone mapping curve 30: 30-1 to 30-4(refer to FIGS. 14 to 16) by using the brightness information 12-1, thereference tone mapping curve 12-3 and the maximum brightness 12-3 a, atone mapping curve applicator 255 applying the tone mapping curve 30:30-1 to 30-4 to the image data 11, and a second image processor 257changing an optical reference signal of the image, on which the tonemapping is performed, to an electrical reference signal. At least one ofthe above mentioned components 251 to 257 may be omitted. The firstimage processor 251, the tone mapping curve generator 253, the tonemapping curve applicator 255 and the second image processor 257 may beimplemented as practically same as or implemented by partially modifyingthe first image processor 213, the tone mapping curve generator 215, thetone mapping curve applicator 217 and the second image processor 219.Therefore, description thereof will be omitted.

Hereinafter a method for controlling the display apparatus according toembodiments will be described with reference to FIGS. 18 and 19.

FIG. 18 is a flowchart illustrating a method for controlling a displayapparatus according to an embodiment.

Referring to FIG. 18, image data and brightness information may begenerated by the image producer terminal apparatus 9 or an imageproducer and then the generated image data and brightness informationmay be transmitted to the display apparatus in the form of image file.

For example, the display apparatus may directly receive image data andmetadata from the image producer terminal apparatus 9 or the imageproducer through a server device or a repeater. Alternatively, thedisplay apparatus may receive image data and metadata acquired from anoptical disc or a separate image file through a signal transmissioninterface.

The brightness information may be acquired by using a histogram that isacquired by accumulating the greatest values (e.g., the maximum valueamong R value, G value and B value) of sub pixel values of each pixel ofthe image. For example, the brightness information may includepercentile information defined based on the histogram.

The display apparatus may receive the image file (302) and acquire imagedata and metadata from the received image file (304).

When the image providing apparatus receives the image file, the imageproviding apparatus may acquire the image data and the metadata from theimage file, and the acquired image data and the metadata may betransmitted to the display apparatus through a predeterminedcommunication standard (e.g., HDMI or USB).

The display apparatus may generate a tone mapping curve based on thebrightness information contained in the metadata (306). For example, thedisplay apparatus may select any one point (knee point) based on atleast two pieces of percentile information (e.g., 50% ile percentileinformation and 99% ile percentile information) contained in thebrightness information, and calculate a coefficient of the function inthe non-linear region based on the at least two pieces of percentileinformation, thereby generating a tone mapping curve. The displayapparatus may generate a tone mapping curve based on the maximumbrightness of the display (e.g., a display panel) mounted on the displayapparatus.

The display apparatus may generate a tone mapping curve to be applied tothe entire image or may generate a plurality of tone mapping curves tobe separately applied to each cut or scene of the image.

The display apparatus may apply the generated tone mapping curve to theimage data (308), and output the image data, to which the tone mappingcurve is applied, to the outside (310).

Accordingly, the display apparatus may appropriately acquire and use thetone mapping curve for the image without receiving the tone mappingcurve.

It is also possible that the above-described generation and/orapplication of the tone mapping curve is performed by an image providingapparatus connected to the display apparatus.

FIG. 19 is a flowchart illustrating a method for controlling a displayapparatus according to another embodiment. A description of the sameparts as those shown in FIG. 18 will be omitted.

Referring to FIG. 19, the image producer terminal apparatus 9 or theimage producer may generate an image file and transmit the image file tothe image providing apparatus and/or the display apparatus through aserver device or a repeater, or an optical disc media or content in theform of file (320).

The image file may include image data and metadata, and the metadata mayfurther include brightness information, the maximum brightness of thereference display apparatus, and the reference tone mapping curve.

The display apparatus may receive the image file or the image data andthe metadata acquired by the image providing apparatus (322), andacquire the brightness information and the reference tone mapping curvefrom the metadata (324).

According to an embodiment, when the display apparatus receives metadatafrom the image producer terminal apparatus or the image producer, thedisplay apparatus may directly acquire the brightness information andthe reference tone mapping curve. Alternatively, when the displayapparatus receives metadata from the image providing apparatus, thebrightness information and the reference tone mapping curve may beacquired by the image providing apparatus.

The metadata may include the brightness information, information on themaximum brightness of the reference display apparatus, and the referencetone mapping curve.

The display apparatus may acquire or generate a tone mapping curve basedon at least one of the brightness information, information on themaximum brightness of the reference display apparatus, and the referencetone mapping curve (326).

For example, the display apparatus may compare the maximum brightness(e.g., the maximum brightness of the reference display apparatus)corresponding to the reference tone mapping curve, with the maximumbrightness of the display of the display apparatus. When the maximumbrightness corresponding to the reference tone mapping curve is the sameas the maximum brightness of the display of the display apparatus basedon a result of comparison, the display apparatus may select the receivedreference tone mapping curve as a tone mapping curve to be applied tothe image data.

When the maximum brightness corresponding to the reference tone mappingcurve is different from the maximum brightness of the display, thedisplay apparatus may generate and acquire a tone mapping curve by usingat least one of the brightness information and the reference tonemapping curve.

For example, when the maximum brightness of the display is greater thanthe maximum brightness of the reference display apparatus, the displayapparatus may place a knee point of the reference tone mapping curverelatively far from the origin. In other words, the display apparatusmay select a knee point of a new tone mapping curve by increasing adistance between the knee point of the reference tone mapping curve andthe origin. Sequentially, the display apparatus may calculate acoefficient using the coefficient of the reference tone mapping curveand/or the brightness information, and then calculate a function of thenon-linear region based on the calculated coefficient, therebygenerating a tone mapping curve by using the selected knee point and thecalculated function of the non-linear region.

On the other hand, when the maximum brightness of the display is lessthan the maximum brightness corresponding to the reference tone mappingcurve, the display apparatus place a knee point of the reference tonemapping curve relatively close to the origin. In other words, thedisplay apparatus may select a knee point of a new tone mapping curve byreducing a distance between the knee point of the reference tone mappingcurve and the origin. Sequentially, the display apparatus may calculatea coefficient using the coefficient of the reference tone mapping curveand/or the brightness information, and then calculate a function of thenon-linear region based on the calculated coefficient, therebygenerating a tone mapping curve by using the selected knee point and thecalculated function of the non-linear region.

Accordingly, it may be possible to appropriately select or generate atone mapping curve to be applied to the image data.

The display apparatus may generate a tone mapping curve to be applied tothe entire image or may generate a plurality of tone mapping curves tobe separately applied to each cut or scene of the image.

The display apparatus may apply the generated tone mapping curve toimage data (328).

The image data to which the tone mapping curve is applied may bevisually output to the outside via the display (330).

As is apparent from the above description, according to the proposeddisplay apparatus, method for controlling the same, and image providingapparatus, it may be possible to directly generate a tone mappingfunction to be applied to an image, which is to be displayed on thedisplay apparatus and/or the image providing apparatus, withoutreceiving the function from the outside.

It may be possible to generate a tone mapping curve, which isappropriate for an image to be displayed with brightness value of theimage that is provided by the display apparatus and/or the imageproviding apparatus, and/or it may be possible to receive brightnessvalue of the received image and the reference tone mapping curve andthen generate a tone mapping curve, which is appropriate for an image tobe displayed, based on the brightness value of the received image andthe reference tone mapping curve.

Since it is not required to add the tone mapping curve to the metadataof the image and then transmit the metadata to the display apparatusand/or the image providing apparatus, the display apparatus and/or theimage providing apparatus may acquire a tone mapping curve, which isappropriate for an image to be displayed despite of using acommunication standard in which the size of transmittable metadata isrelatively small.

Since it is not required to transmit a tone mapping curve correspondingto each image or each part of image (e.g., scene) to the displayapparatus and/or the image providing apparatus to implement a dynamichigh dynamic range, it may be possible to obtain the economic effect.

A method for controlling a display apparatus according theabove-described embodiment may be implemented in the form of a programexecuted by a variety of computer implementations. The program mayinclude program instructions, data files, and data structures as itselfor a combination therewith. The program may be designed or manufacturedby using higher level code executed by the computer by using aninterpreter, as well as by using a machine code that is produced by acompiler. In addition, the program may be particularly designed toimplement the control method of the above mentioned method forcontrolling a display apparatus or may be implemented by using variousfunctions or definition that are well-known and available to a group ofordinary skill in the computer software field.

Programs for implementing method for controlling a display apparatus maybe recorded on a recording medium readable by a computer. The recordingmedium readable by a computer may include various types of hardwaredevices capable of storing a particular program executed in response toa call from a computer, e.g. magnetic disk storage media such as a harddisk or a floppy disk, optical media such as a magnetic tape, a compactdisc (CD) or a DVD, magneto-optical media such as a floptical disk, andsemiconductor memory devices such as ROM, RAM, or flash memory.

Hereinbefore a variety of embodiments of the display apparatus, methodfor controlling the same, and image providing apparatus are described,but is not limited thereto. A variety of embodiments which isimplementable by those skilled in the art by correcting and modifyingbased on the above mentioned embodiment may correspond to the abovementioned display apparatus, method for controlling the same, and imageproviding apparatus. For example, when the above-mentioned techniques isexecuted in a different order from the above-mentioned method, and/orthe above-mentioned components such as system, structure, device andcircuit is coupled or combined in a manner different from theabove-mentioned method or is replaced or substituted by other componentsor equivalents, the same or the similar result as the above-mentioneddisplay apparatus, method for controlling the same, and image providingapparatus may be achieved and those may correspond to an example of theabove-mentioned display apparatus, method for controlling the same, andimage providing apparatus.

Although a few embodiments of the present disclosure have been shown anddescribed, it would be appreciated by those skilled in the art thatchanges may be made in these embodiments without departing from theprinciples and spirit of the disclosure, the scope of which is definedin the claims and their equivalents.

What is claimed is:
 1. A display apparatus comprising: a processorconfigured to generate a tone mapping curve by using brightnessinformation, received by the display apparatus, of an image, and areference tone mapping curve, received by the display apparatus, and toapply the tone mapping curve to image data, received by the displayapparatus, of the image; and a display configured to display the imagebased on the image data having the tone mapping curve applied thereto,wherein the tone mapping curve includes a linear region extending froman origin of the tone mapping curve to a knee point of the tone mappingcurve and having a slope set to a ratio of a maximum brightness of theimage to a maximum brightness of the display and maintained at the ratiofor the entire linear region, and a continuously non-linear regionextending from the knee point to a point of the tone mapping curvecorresponding to the maximum brightness of the display, to thereby map abrightness range of the image to a brightness range of the display, theprocessor is configured to generate the tone mapping curve by increasinga distance between the origin of the tone mapping curve and the kneepoint of the tone mapping curve when the maximum brightness of thedisplay is greater than a maximum brightness corresponding to thereference tone mapping curve, as compared to a case in which the maximumbrightness of the display is less than the maximum brightnesscorresponding to the reference tone mapping curve, and the processor isconfigured to generate the tone mapping curve by reducing a distancebetween the origin and the knee point when the maximum brightness of thedisplay is less than the maximum brightness corresponding to thereference tone mapping curve, as compared to the case in which themaximum brightness of the display is greater than the maximum brightnesscorresponding to the reference tone mapping curve.
 2. The displayapparatus of claim 1, wherein the brightness information of the imagecomprises percentile information of a brightness distribution that isacquired by accumulating a maximum brightness value of each pixel of theimage, and the maximum brightness value is the largest value among abrightness value of a R sub pixel, a brightness value of a G sub pixel,and a brightness value of a B sub pixel.
 3. The display apparatus ofclaim 1, wherein the processor is configured to select the referencetone mapping curve as the tone mapping curve when the maximum brightnessof the display is the same as the maximum brightness corresponding tothe reference tone mapping curve, and the processor is configured togenerate the tone mapping curve by using at least one of the brightnessinformation and the reference tone mapping curve, when the maximumbrightness of the display is different from the maximum brightnesscorresponding to the reference tone mapping curve.
 4. The displayapparatus of claim 1, wherein the display apparatus is configured toreceive the image data and the brightness information by using HighDefinition Multimedia Interface (HDMI) standard.
 5. The displayapparatus of claim 1, wherein the non-linear region is representable bya quadratic function.
 6. A method comprising: by a display apparatus,receiving image data of an image, and-brightness information of theimage, and a reference tone mapping curve; generating a tone mappingcurve by using the brightness information and the reference tone mappingcurve; applying the tone mapping curve to the image data; anddisplaying, on a display, the image based on the image data having thetone mapping curve applied thereto, wherein the tone mapping curveincludes a linear region extending from an origin of the tone mappingcurve to a knee point of the tone mapping curve and having a slope setto a ratio of a maximum brightness of the image to a maximum brightnessof the display and maintained at the ratio for the entire linear region,and a continuously non-linear region extending from the knee point to apoint of the tone mapping curve corresponding to the maximum brightnessof the display, to thereby map a brightness range of the image to abrightness range of the display, the generating the tone mapping curvegenerates the tone mapping curve by increasing a distance between theorigin of the tone mapping curve and the knee point of the tone mappingcurve when the maximum brightness of the display is greater than amaximum brightness corresponding to the reference tone mapping curve, ascompared to a case in which the maximum brightness of the display isless than the maximum brightness corresponding to the reference tonemapping curve, and the generating the tone mapping curve generates thetone mapping curve by reducing a distance between the origin and theknee point when the maximum brightness of the display is less than themaximum brightness corresponding to the reference tone mapping curve, ascompared to the case in which the maximum brightness of the display isgreater than the maximum brightness corresponding to the reference tonemapping curve.
 7. The method of claim 6, wherein the brightnessinformation of the image comprises percentile information of abrightness distribution that is acquired by accumulating a maximumbrightness value of each pixel of the image, and the maximum brightnessvalue is the largest value among a brightness value of a R sub pixel, abrightness value of a G sub pixel, and a brightness value of a B subpixel.
 8. The method of claim 6, wherein the generating comprises atleast one of selecting the reference tone mapping curve as the tonemapping curve, when the maximum brightness of the display is the same asthe maximum brightness corresponding to the reference tone mappingcurve, and generating the tone mapping curve by using at least one ofthe brightness information and the reference tone mapping curve, whenthe maximum brightness of the display is different from the maximumbrightness corresponding to the reference tone mapping curve.
 9. Themethod of claim 6, wherein the receiving comprises receiving the imageand the brightness information by using High Definition MultimediaInterface (HDMI) standard.
 10. The method of claim 6, wherein thenon-linear region is representable by a quadratic function.